Cutting appliance for sewing-machines.



K. A. STROHMAIER. CUTTING APPLIANCE FOR SEWING MACHINES.

APPLICATION FILED APR. 3, 1911.

1,012,746, Patehted Dec. 26, 1911.

coumau PLANDGRAPN co.. WASHINGTON, n. c

KARL ANTON STROHMAIER, OF CHEMNITZ, GERMANY.

CUTTING APPLIANCE FOR SEWING-MACHINES.

Specification of Letters Patent.

Application filed April 3, 1911.

Patented Dec. 26, 1911. Serial No. 618,671.

To all whom it may concern:

Be it known that I, KARL ANTON STRoH- MAIER, a subject of the Emperor of Germany, residing at Chemnitz, Germany, have invented Improvements in Cutting Appliances for Sewing-Machines, of which the following is a specification.

This invention. relates to cutting appliances for use in sewing machines, for cutting off or trimming the edges of material.

Figure 1 of the accompanying illustrative drawings-is a sectional side elevation of a machine embodying this invention. Fig. 2 is a transverse section, and, Fig. 3 is a plan with the mechanism cover plate removed.

A star-shaped body constituted by a num ber of knives c is fixed upon a shaft Z) upon which is mounted an arm 11, the attachment of the arm being effected by means of an adjustable clamp h which is tightly secured after adjustment by clamping screws j. A link 70 connects the arm 11 to the arm Z of a two armed lever mounted upon a bolt m and to the arm n of which is attached an arm 0 which is connected to the strap of an eccentric s mounted on the driving shaft 79. On rotating the eccentric s a short forward and backward partial rotation will be imparted to the starshaped knife body 0 so that the particular knife 0 in operative position will cooperate with the stationary knife blade d to give a series of scissor-like cuts. At the same time the knife carrying shaft Z), which is mounted in a bearing a, is forced in a direction to press the operative knife 0 against the fixed knife blade or cutting edge (Z by a rod 6 carried in a bearing f and formed with a screw threaded portion that I terminates in a head 9. A cap ris provided for the protection of the moving parts that project above the cover plate or work table of the machine. When a knife 0 becomes blunt the clamping screw j is loosened, the star-shaped knife body is partially rotated until the next knife 0 is in operative position and the clamping screw j is again tightened up.

What I claim is 1. In a cutting appliance for a sewing machine, a stationary knife blade, a rotary spindle, a boss on said spindle, a number of knives projecting radially from said boss in a plane that is vertical to said stationary knife blade, an arm adjustably clamped on said spindle, a two-armed lever, a link connecting one end of said lever to said arm, an operating shaft, an eccentric on said shaft, a strap on said eccentric connected to the other arm of said lever, and means for pressing said knives toward said stationary knife blade.

2. In a cutting appliance for a sewing machine, a stationary knife,'a spindle, a boss on said spindle a number of knives projecting radially from said boss in a plane that is vertical to said stationary knife, a bearing in which said spindle is mounted to slide and rotate, an arm adjustably clamped on said spindle, a two-armed lever, a link connecting one end of said lever to said arm, an operating shaft, an eccentric on said shaft, a strap on said eccentric connected to theother arm of said lever, an

adjusting screw adapted to bear on the end of said spindle and move it in said bearing toward said stationary knife, and a bracket in which said screw is carried.

Signed at Chemnitz, Saxony,

this twentieth day of March 1911.

KARL ANTON STROHMAIER.

Witnesses:

WM. WASHINGTON BRUNSWICK, FRITZ EUGEN VENBERS.

Germany,

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

